1. Field of the Invention
The present invention relates to a display device, and more particularly, to a liquid crystal display device and a method for fabricating the same. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for enhancing the brightness of a liquid crystal display device.
2. Description of the Related Art
Various types of portable electronic devices, such as mobile phones, personal digital assistants (PDA), and note book computers are now in use because of their small size, light weight, and low power consumption. Flat panel display devices, such as liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), and vacuum fluorescent displays (VFDs), have been developed for such portable electronic devices. Of these flat panel display devices, the LCDs are currently in mass production because of their simple driving scheme and superior image quality.
FIG. 1 is a cross-sectional view showing an LCD device 1 in accordance with the related art. As shown in FIG. 1, the LCD device 1 includes a lower substrate 5, an upper substrate 3, and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. A driving device array of a plurality of pixels is formed on the lower substrate 5. A switching device 9, such as a thin film transistor (TFT) is formed in each pixel. A pixel electrode 6 connected to the TFT is formed on the lower substrate 5.
A black matrix 8 and a color filter layer 2 are positioned on the upper substrate 3 for implementing the display of colors. A common electrode 4 is formed on the upper substrate 3. An alignment layer for aligning liquid crystal molecules of the liquid crystal layer 7 is provided on the lower substrate 5.
The lower substrate 5 and the upper substrate 3 are attached to each other by a sealant (not shown) formed at the periphery of the substrates. A constant cell gap is maintained by a spacer (not shown) positioned between the lower substrate 5 and the upper substrate 3. Also, the liquid crystal layer 7 is formed between the lower substrate 5 and the upper substrate 3. The TFT switches an electric field between the common electrode 4 and the pixel electrode 6. The electric field reorients the liquid crystal molecules in the liquid crystal layer to control light passing through the liquid crystal layer, thereby displaying information.
The driving device array on the lower substrate 5 is formed by a driving device array process, and a color filter on the upper substrate 3 is formed by a color filter process. A spacer forming process and a liquid crystal layer forming process are then performed. Lastly, the lower substrate 5 and the upper substrate 3 are sealed together with a sealing process.
In the driving device array substrate process, a plurality of gate lines and data lines are formed first for defining pixel regions on the lower substrate 5. Then, a thin film transistor 9 connected to the gate lines and the data lines is formed in each pixel region. Then, the pixel electrode 6 connected to the thin film transistor for driving the liquid crystal layer by receiving a signal through the thin film transistor is formed in each pixel region.
In the color filter substrate process, the black matrix 8 is formed first on the upper substrate 3. Then, the color filter 2 is formed for implementing red (R), green (G), and blue (B) colors. The common electrode 4 is then formed on the color filter layer 2.
In the related art LCD device, light is supplied from a backlight provided at a lower surface of the lower substrate 5. An image is displayed by controlling an amount of light passing through the liquid crystal layer from the backlight. However, light incident on the black matrix 8 from the backlight is absorbed by the black matrix 8. Accordingly, light incident on the black matrix 8 is lost and not used in displaying an image.